In the related and relevant “below the hook” art technology, shipping containers and similar loads are typically lifted by means of a “spreader bar” assembly that can generally consist of end caps that insert into each end of a pipe segment wherein the end caps are connected by a “Y” cable to a crane or other lifting mechanism. Spreader bar assemblies of various lengths can be made by using spreader bar pipe connecting sleeve in-between different lengths of pipe.
A variety of prior art patent documents relate to spreader bar assemblies or couplings for connecting a range of pipe segments. For instance, U.S. Pat. No. 160,301 to Brancher et al. and U.S. Pat. No. 367,578 to Babb are related to pipe couplings. Referring specifically to FIG. 4 in Brancher, a pipe connector is shown for joining two sections of pipe. Babb also discloses an apparatus for coupling two sections of pipe with reference to FIGS. 2 and 3 of Babb. However, the coupling devices shown in these two references are merely indicative of known prior devices for joining two segments of pipe.
Four patent documents in the name of Khachaturian relate to spreader bar assemblies. Namely, U.S. Pat. No. 4,538,849 discloses an adjustable spreader bar assembly having end portions which can be removably fitted to the ends of a section of pipe. The end caps disclosed in this patent can be most readily seen in FIGS. 4 through 11 of Khachaturian.
U.S. Pat. Nos. 6,079,760 and 6,296,288 relate to a multi-part spreader bar arrangement including a plurality of connectible sections including a pair of bar sections and a pair of end caps and also including detachable connections between the connectible sections. Referring specifically to the figures, the couplings and end caps disclosed in this patent are of threaded engagement.
U.S. Patent Application Publication No. 2005/0199567 to Tardiff discloses a spreader bar apparatus including a plurality of pipe sections which are connected through the use of a coupling wherein the coupling is connected to the pipe segments through the use of removable pins, as shown in FIGS. 1, 3, and 6 of Tardiff.
U.S. Pat. Nos. 7,967,352 and 8,382,175, both to DiMartino, disclose an end cap and a pipe connection sleeve, respectively for use in a spreader bar assembly. The end cap and pipe connection sleeve of DiMartino disclose an end cap and pipe connection sleeve having end plates (e.g., 26, 62, and 68) affixed substantially centered on an end portion thereof (e.g., 32, 60, and 66) as shown in FIGS. 3 and 6 of DiMartino.
Several disadvantages are known in the prior art. Generally, the installation or detachment of items for use in different lifts is a time consuming and laborious process. Usually, a user must stock pile various sized completed assemblies (spreader pipes attached to end caps, etc.) in order to handle different sized loads. Additionally, it is known that many of these prior art assemblies are made in permanent assemblies, such as end caps welded to spreader pipes, or in a manner that is difficult to assemble/disassemble (a multitude of bolts and nuts, etc.). Even further, it is known that tremendous pressures can be applied to the spreader bar assemblies during use and the prior art assemblies (especially assemblies having multiple spreader bar pipes joined together), exhibit sagging (See FIG. 1), and in some cases, as a result, even may buckle and fail under such pressures, especially at the connection joints of the spreader bar pipes (i.e., where the pipes are connected together), due to seating at the junctions of the spreader bar pipe ends and the pipe connection sleeve. As such, there remains a need for a pipe connecting sleeve for use with a load spreader bar assembly that substantially reduces or eliminates sagging, has improved strength, and provides a quick connect and disconnect for assembly/disassembly, but that also creates a tight connection under load, allows for easier storage and transport of spreader bars, provides optional pipe connection sleeve that allows for use with different diameter pipes, and allows for more than one pipe connection sleeve to be used in a single assembly while maintain load capacity.